Yes, I recognize this too

. It's one of the most common riffs guitar beginners learn.
Other common reoccuring songs are
The House of the Rising Sun,
Purple Haze (Jimi Hendrix) and
Smells Like Teen Spirit (Nirvana). I can play both the
Toccata (on keyboard, though only the intro up to when the faster part starts) and
Smoke On The Water (on guitar) and the
Toccata is the more difficult one of these two.
I can play the other three riffs too, and if I list those five in order of difficulty I think I'd say the
Toccata is the most difficult (because of the melody and the changes of speed of the notes):
- Toccata (not easy for beginners, there are definitely more easy songs for beginners on keyboard)
- Purple Haze (not particularly easy for beginners, you have to have played a while to manage it)
- The House of the Rising Sun (it is a bit tricky partly because it's in 3/4)
- Smells Like Teen Spirit (Nirvana) (quite easy, though you need to know how to play chords)
- Smoke On The Water (very easy)
(1 = most difficult, 5 = least difficult)
Some more examples here:
Forbidden Riffs In Guitar Stores (leftyfretz)
(note: I was a bit surprised
Sweet Child O’ Mine (Guns ‘N Roses) was on the list. It is actually a quite tricky thing to play, because (1) it's originally played very high on the fretboard (i.e. tight frets) and (2) it may sound simple, but it is a quite tricky pattern to play. I can only play it slowly

.)